From 5669ccee21d87622f30a724b3fe0d04ec5b0afae Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sun, 24 Mar 2013 18:58:04 +0100 Subject: [PATCH] uprobes: Introduce copy_to_page() Extract the kmap_atomic/memcpy/kunmap_atomic code from xol_get_insn_slot() into the new simple helper, copy_to_page(). It will have more users soon. Signed-off-by: Oleg Nesterov Acked-by: Anton Arapov Acked-by: Srikar Dronamraju --- kernel/events/uprobes.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 093866547fe3..b8255eaca190 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -194,6 +194,13 @@ static void copy_from_page(struct page *page, unsigned long vaddr, void *dst, in kunmap_atomic(kaddr); } +static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len) +{ + void *kaddr = kmap_atomic(page); + memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len); + kunmap_atomic(kaddr); +} + static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode) { uprobe_opcode_t old_opcode; @@ -1227,9 +1234,7 @@ static unsigned long xol_take_insn_slot(struct xol_area *area) static unsigned long xol_get_insn_slot(struct uprobe *uprobe) { struct xol_area *area; - unsigned long offset; unsigned long xol_vaddr; - void *vaddr; area = get_xol_area(); if (!area) @@ -1240,10 +1245,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) return 0; /* Initialize the slot */ - offset = xol_vaddr & ~PAGE_MASK; - vaddr = kmap_atomic(area->page); - memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES); - kunmap_atomic(vaddr); + copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES); /* * We probably need flush_icache_user_range() but it needs vma. * This should work on supported architectures too.